Re: Subwoofer Power Supply Problem

I just finished replacing all 6 capacitors on the PSU circuit board. All TREC caps were changed to Nichicon caps. The only problem encountered, was that the solder pump could not fit to clear the some of the capacitor holes, so I had to use the method suggested on this site of using a steel needle.

The picture of the power supply shows which capacitors were changed, all 6 are circled. The capacitors with red circles were the blown caps, the caps with red and blue circles were fine.

After testing the subwoofer for...

Re: Subwoofer Power Supply Problem

I looked at the PSU board again and the other 4 small capacitors are all 85c made by TREC - Transcend Electrolytic(Shenzhen)Co.,Ltd.

(2X) REC , SR , 47uF , 16V , 85C , 124mA , 5x11mm
(2X) REC , SR , 470uF , 16V , 85C , 440mA , 8x12mm
(2X) REC , SR , 1000uF , 25V , 85C , 925mA , 10x20mm

It was late at night when I went through all the data sheets and I was looking for replacements for all the other caps listed above. Those data sheets can make you go crazy with all those rows and columns, thanks for catching...

Re: Subwoofer Power Supply Problem

I am hoping that I will get an improvement in either the power or sound quality. Can you guys tell me which side the filter capacitors are on that I am replacing - primary or secondary. In a SMPS, I know the primary is connected to the AC power and secondary is next to ATX connectors, but on this linear PSU circuit it is not clear.

Now, if I replace the 85C caps with 105C caps then I should not need to make any holes for ventilation. As for the digikey link that toasty sent, the size of the capacitor has to be 10mm in diameter, the...

Re: Subwoofer Power Supply Problem

I had searched the internet and could not find any information on the capacitors. When I called technical support at Onix (subwoofer manufacturer), they did not know either and did not have the service manual since the sub was discontinued.

So, thanks jpdoe for finding this information on the REC capacitors for me. I see in the data sheet that ripple current for my capacitors is 925mA, however it does not state what the esr values are for the capacitors. Should I be looking for low esr capacitors ?

The subwoofer is...

I purchased the subwoofer 'Rocket ULW-10' around 2005 and recently was experiencing a humming noise coming from the sub. So I researched the problem on the internet and it was suggested on various forums that this could be a capacitor issue.

After checking the audio source and for grounding issues, I then decided to open up the subwoofer plate amplifier. What I discovered was that 2 of the capacitors on the power supply board were blown.

The 2 capacitors had the following specifications:
'PEC' or 'REC' , SR , 1000uF , 25V , 85C

Now I am assuming...